It turns out that the philospher Xenophan (430 - 354 B.C.) is known for his writings on the history of his own times, preserving the sayings of Socrates, and the life of ancient Greece. He was also a scholar of Plato and Aristotle capturing much of their philosophy. Aristotle was a special favorite of Islamic scholars and thinkers, such as Avicenna and Averroes, particularly for his "Ethics." Much of what remains of the Greek classics was saved by Xenophan, translated into classical Arabic and interpreted by the Arabs.
There is the tie-in and the letter "x" for our alphabet project that describes Islamic subjects that begin with an "x". Thank you for looking. Now we all know! Peace be with you!